166
FXUS65 KBYZ 101101
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
501 AM MDT THU SEP 10 2026
KEY MESSAGES
- ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS TODAY. WINDS WILL
BE STRONGEST OVER THE FOOTHILLS WEST OF BILLINGS.
- A PATTERN CHANGE BRINGS COOLER TEMPERATURES AND MULTIPLE CHANCES
FOR PRECIPITATION FRIDAY THROUGH THE WEEKEND, INCLUDING
MOUNTAIN SNOW.
- CHANCE (40-60%) FOR FOOTHILLS LOCATIONS TO SEE THEIR FIRST FROST
MONDAY MORNING.
DISCUSSION
NEXT 7 DAYS...
ANOTHER DAY OF SUMMER LIKE WEATHER IS IN STORE FOR OUR REGION
BEFORE WE GET OUR FIRST TASTE OF FALL. TODAY, AHEAD OF THE COLD
FRONT, HIGH TEMPS WILL BE 10 DEGREES ABOVE AVERAGE FOR MOST OF US
WITH HIGHS IN THE 80S. RELATIVE HUMIDITY WILL ALSO REMAIN QUITE
LOW AS THE PREVAILING WIND THROUGH THE LOW LEVELS WILL STILL BE
WESTERLY (DOWNSLOPE). THERE IS ALSO A GOOD SIGNAL FOR GUSTY WINDS
THROUGH THE DAYTIME HOURS TODAY. THE STRONGEST WINDS ARE FORECAST
IN THE FOOTHILLS / GAP AREAS TO THE WEST OF BILLINGS WHERE GUSTS
IN THE 30S MPH WILL BE COMMON THIS AFTERNOON. THE OTHER AREA OF
HIGHER WIND GUSTS WILL BE FAR SE MONTANA AS THE EXPOSED PLAINS
WILL ALLOW FOR INTERRUPTED WINDS GUSTING UP TO 30 MPH. THESE
CONDITIONS WILL RESULT IN ELEVATED TO CRITICAL FIRE WEATHER ACROSS
THE CWA WITH THE FOCUS IN THOSE REGIONS MENTIONED ABOVE DUE TO
THE STRONGER WINDS.
OUR FIRST REAL FALL COLD FRONT WILL MOVE THROUGH THURSDAY NIGHT
INTO EARLY FRIDAY MORNING BRINGING IN MUCH COOLER TEMPERATURES.
WHILE MUCH OF THE REGION WILL BE 10 DEGREES ABOVE AVERAGE TODAY,
THE HIGHS ON FRIDAY WILL LIKELY BE AROUND 5 TO 10 DEGREES BELOW
AVERAGE. THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS TO
ACCOMPANY THE FROPA AS WELL AS LINGER THROUGH THE DAY FRIDAY,
ESPECIALLY IN THE WESTERN PART OF THE CWA. WE WILL THEN REMAIN
UNDER THE MAIN UPPER LEVEL JET STREAM THROUGH THE WEEKEND WHICH
WILL ALLOW FOR TEMPS TO CONTINUE TO COOL OFF AS WELL AS ALLOW FOR
SEVERAL CHANCES FOR PRECIPITATION.
EXACT TIMING, COVERAGE, AND AMOUNTS OF PRECIP ARE STILL IN
QUESTION. WHILE MOST OF THE MODELS AND THEIR ENSEMBLES DO HAVE
GOOD AGREEMENT AROUND THE SYNOPTIC SCALE PATTERN, THE MESOSCALE
FEATURES ARE STILL YET TO BE AGREED UPON. REGARDLESS OF WHAT
THE DETAILS ARE, COOL TEMPS AS WELL AS ROUNDS OF SHOWERS SHOULD
BE ANTICIPATED. WITH THESE COOLER TEMPS THERE IS A DECENT CHANCE
OF THE FIRST FROST OR FREEZE FOR SOME LOCATIONS. THE COLDEST AREAS
WILL LIKELY BE THE FOOTHILLS REGION FROM THE PARADISE VALLEY UP
THROUGH JUDITH GAP. THESE AREAS HAVE A 40-60% CHANCE OF A FROST
(36F) MONDAY MORNING AND A 20-40% CHANCE OF THEIR FIRST FREEZE.
ACROSS THE ENTIRE CWA, NO MATTER HOW COLD IT IS, THE COOLEST
TEMPERATURES OF THE SEASON SO FAR ARE LOOKING VERY LIKELY THIS
WEEKEND.
NATURALLY, THE CHANCE FOR PRECIP BEHIND A COLD FRONT IN SEPTEMBER
INVITES THE QUESTION OF MOUNTAIN SNOW. THE LOWEST SNOW LEVEL OF
THE WEEKEND STILL HAS VERY LARGE DISCREPANCIES. OVER THE MOUNTAINS
OF SOUTH CENTRAL MONTANA THE NBM 10-90 PERCENTILE RANGE MONDAY AM
HAS SNOW LEVELS RANGING BETWEEN 5KFT AND 8.5KFT. IT IS IMPORTANT
TO NOTE THAT ANY SNOW ACCUMULATIONS, REGARDLESS OF THE SNOW LEVEL,
WILL BE CONFINED TO ABOVE 9KFT. THIS COULD RESULT IN SOME TRAVEL
IMPACTS ON THE BEARTOOTH PASS, PRIMARILY ON SUNDAY. NO MATTER WHAT
THE PRECIP TYPE IS THOUGH, THE COMBINATION OF WET AND COLD
CONDITIONS WILL RESULT IN HAZARDOUS BACKCOUNTRY CONDITIONS FOR THE
ENTIRE WEEKEND.
AS WE GO INTO FIRST HALF OF NEXT WEEK, THERE IS A GOOD SIGNAL
THAT WE WILL REMAIN IN AN ACTIVE PATTERN. SEVERAL SHORTWAVES COULD
PIVOT THROUGH THE REGION BRINGING REPEATED ROUNDS OF PRECIP AS
COOLER THE AVERAGE TEMPERATURES HANG AROUND. WMR
AVIATION
12Z TAF/AVIATION DISCUSSION...VFR CONDITIONS WILL PREVAIL THROUGH
THE PERIOD. WESTERLY WINDS GUSTING 15-30 KTS ARE EXPECTED TODAY,
STRONGEST ALONG THE WESTERN FOOTHILLS (KLVM, K6S0, K3HT). A DRY
COLD FRONT WILL BRING A WIND SHIFT LATE THIS EVENING INTO THE
OVERNIGHT HOURS. WINDS IN THE GENERALLY WIND SHADOWED BIGHORN
FOOTHILLS (KSHR) WILL LIKELY GET GUSTY (25KTS) FROM THE WEST AHEAD
OF THIS WIND SHIFT AFTER 03Z, CONTINUING INTO THE EARLY MORNING
HOURS UNTIL THE FRONT ARRIVES AND SHIFTS WINDS NORTHERLY. CHAMBERS
PRELIMINARY POINT TEMP/POPS
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 087 053/069 049/066 046/065 043/064 041/065 043/065
0/U 01/B 31/B 55/T 40/B 00/B 01/B
LVM 086 048/073 043/066 039/064 037/063 034/066 040/067
0/N 03/T 31/N 56/T 41/B 00/U 01/B
HDN 090 049/072 045/070 043/070 039/064 036/069 039/068
0/K 00/B 31/B 55/T 50/B 00/U 00/B
MLS 088 056/071 047/066 046/068 044/060 039/066 043/068
0/U 01/B 21/E 65/T 61/N 00/U 11/B
4BQ 089 056/075 047/071 049/073 044/064 039/069 044/071
0/U 00/U 31/B 64/T 41/B 00/U 10/B
BHK 089 052/074 041/067 041/067 041/061 035/068 040/072
0/U 00/B 12/W 76/T 72/W 10/U 11/B
SHR 088 051/075 041/071 044/072 037/065 035/070 039/069
0/U 02/U 31/B 43/T 31/U 00/U 11/B
BYZ WATCHES/WARNINGS/ADVISORIES
MT...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS
EVENING FOR ZONES 123-124-127-133.
WY...NONE.
WEATHER.GOV/BILLINGS
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